1. Field of the Invention
The invention relates in general to a soft program method, and more particularly to a soft program method with reduced bit-by-bit soft program time.
2. Description of the Related Art
In the present age, non-volatile memory devices have become more popular for use in various electronic devices, such as cellular telephones, digital cameras, personal digital assistants, mobile computing devices, non-mobile computing devices and so on. For example, flash memory is one of the most popular non-volatile semiconductor memories applied in the present age. Generally, flash memory includes flash memory cells with programmable threshold voltages, so that each of the flash memory cells can be selectively programmed to indicate logic datum “1” and indicating logic datum “0”.
Conventionally, flash memory often suffers over-erase issue due to the process inconsistencies. In the present skill, soft program method has been introduced for recovering bits suffering over-erase issue. However, how to find a decent soft program method capable of reducing time and cost required by soft program operation has become a prominent object for the industries.